Two-stroke-cycle internal-combustion engine.



E. HURLBRINK.

TwosTRo| E CYCLE INTERNAL comusloN ENGINE.

APPLICATION FILED DEC. I6. |913.

Patented July 23, 19118.

,IIIIIII IIIIIIIII minesses: J 6m Jvea i f7 any UNITED STATES PATENTOFFICE.

TWO-STROKE-CYCLE INTERN AL-COMBUSTION ENGINE.

Specication ot Letters Patent.

Patented July 23, 1918.

Application tiled December 18, 1913. Serial No. 807,181.

To all whom it may concern Be it known that I, ERNST HURLBRINK,

i a subject. of the Emperor of Germany, residing in Berlin-Friedcnau, inGermany, have invented new and useful Improvements in Two-Stroke-CycleInternal-Combustion Enines; and I do herebydeclare the following to be afull, clear, and exact description of the same.

Hitherto, it has been necessary to construct two-stroke, cycle internalcombustion engines of any considerable capacity with pistons working inopposite directions, in order to secure a. more or less satisfactoryruiming of the engine. Such machines have, however, well-knowndrawbacks, s0 that the use of motors of this type is confined to specialcases. As an instance of such drawbacks, the fact may be mentioned thatmotors of the above-mentioned type cannot be used to drive vessels, sothat it has been sought to build also combustion engines of very largecapacity (for instance, 2000 horse power per cylinder) with only asingle working piston in each cylinder. In spite of the great number ofdifferent constructions and experiments that have been made to this end,however, it has hitherto been impossible to reach a satisfactorysolution of this problem.

It is well-known that, in motors of the type referred to, admissionports overrun by the working piston must be provided in the Wall of theworkin cylinder, while the exhaust takes place at tlg a suitable way ofinsuring a satisfactory scavenging of the cylinder by' the combustiongases has not yet been found.

I have found that, in order to secure a satisfactory scavenging of thecylinder, it is necessary to provide a smooth path for the scavengingair which enters through the admission ports of the Working cylinder andflows along the walls of the latten toward the exhaust ports, free fromany deflection or backing up, and in the same manner as the gases flowfrom the admission ports to the exhaust in motors having two pistonsworking in opposite directions.

The annexed drawing is a diagrammatic, longitudinal section of asingle-action, twostroke engine embodyin one illustrative form of myinvention. t will be understood, however, that the invention is clearlyapplicable to double-action, two-stroke cycle motors.

e cylinder head; but

Referring to the drawings, 1 is the work i ing piston, 7 is the workingc linder, .and 3 are admission` ports provided in the walll2 of theworking cylinder. The piston 1 overruns the admission ports 3 at the endof its working stroke, and at the beginning ofits compression stroke. 44 y 8 is a substantially semi-spherical cylinder head, or cover, and 5 5are two exhaust cylinders of smaller diameter than the working cylinder,and disposed adjacent to the semi-spherical cylinder headS, said exhaustcylinders communicating with the working cylinder 7.

6 6 are exhaust ports provided in the exhaust cylinders, and 4 1 areauxiliary pistons working in the exhaust cylinders and overrunningthe'exliaust ports 6 6.

The rods of the auxiliary pistons 4 4 are connected by means of drivinglinks not shown in the drawing, with the piston rod of the main workingpiston 1, or to the crank-,shaft of the motor, the construction andarrangement being such that the auxiliary pistons 4 4: control theexhaust ports 6--6 in accordance with the well-known twostroke cycle.

As shown in the drawing, the axes ca .z: of the auxiliary cylinders 5 5form an angle with the axis g/ y of the main-workin cylinder 7, suchangle a in the drawing eing less than a right-angle, but it will beunderstood that said angle may equal, or even exceed, a right-angle.

Between the semi-spherical cylinder head 8 and the exhaust cylinders 5 5are provided curved portions 9 and 10, which, in conjunction with thesemi-spherical cylinder head, form a smooth transit from the Walls 2 ofthe main workingcylinder to the `walls of the exhaust cylinders 5, 5.

It will be seen that the scavengin air entering in the main working cyinder 7 through the admission ports 3 will flow along the walls 2 of themain cylinder, and will be directed by means of the semi-sphericalcylinder head 8, and the continuously curved walls 9, 10, into theexhaust cylinders 5 5, so that the scavenging air flows from theadmission ports 3 to the exhaust ports 6, without any deflection orbacking up, in precisely the same manner as in motors with two pistonsworking in opposite dlrections, for instance, motors of the well-knownOschelhuser type.

I am aware that two-stroke cycle interna-l combustion engines. providedwith admission ports in the main working c vlinder and exhaust ports inthe auxiliary cylinders. overrun. respectively. by the main workingpiston and auxiliary pistons. were known before my invention. but what Iclaim is:

1. In a two-stroke cycle internal combustion engine. a main workingcylinder: a main working piston for the latter: admission -ports forsaid main working cylinder. overrun by said main working piston: exhaustcylindeisl of smaller cross-sectional area than the main workingcylinder. disposed adjacent to the head o f the main workmg cylinder andconnnumcatmg with the latter: auxiliary pistons working inthe exhaustcylinders: exhaust ports provided in said exhaust cylinders and overrunby said auxiliary pistons: and means to provide a smooth transit fromthe walls of the main working cylinder into the exhaust cylindersavoiding the deflection and backing up of the scavenging air flowingfrom the adlnission ports of the main cylinder toward the exhaust portsof the exhaust cylinders.

2. In a two stroke cycle internal combust ion engine. a main workingcylinder: a main working piston for the latter: admission ports for saidmain working cylinder overrun by said main working piston: asubstantially semi-spherical cylinder head: exhaust cylinders of smallercross-sectional area than the main working cylinder disposed adjacent tosaid substantially semispherical cylinder head. and standingr at anangle to the axis of the main working cylinder and communicating withthe latter: auxiliary pistons working in said exhaust cylinders: andexhaust ports for said exhaust cylinders. overrun b v the auxiliarypistons.

3. In a two-stroke cycle internal combustion engine. in combination` amain working cylinder: admission ports for the latter. a pluralit\` ofexhaust cylinders communicating with said main working cylinder: andmeans to provide a smooth transitY from the main working cylinder intosaid exhaust cylinders.

4. In a two-stroke cycle internal combustion engine. in combination. amain working cylinder: a plurality of exhaust cylinders communicatingwith the latter; and means including a curved wall intermediate lsaidmain working cylinder and said exhaustcylinders for providing a smoothtransit from the main working cylinder into said exhaust, cylinders.

5. In a two-stroke cycle internal combustion engine, in combination. amain working cylinder: a plurality of exhaust cylinders communicatingwith the latter: and means including curved wall portions intermediatesaid umili working cylinders and said exhaust cylinders to provide asmooth transit from tht` walls of the main working cylinder into theexhaust cylinders.

t'i. In a two-stroke cycle internal combustion engine. in combination. amain working cylinder: a substantially semi-spherical cylinder head forthc saine: a plurality of exhaust cylinders communicating with saidhead; and means to provide a smooth transit from the main workingcylinder through said head into the exhaust cylinders.

T. In a two-stroke cycle internal combustion engine. in combination. amain working cylinder: a substantially semi-spherical cylinder head forthe same: a plurality of exhaust cylinders communicating with 'saidhead: and means including curved wall portions to pro\ide a smoothtransit from the. main working cylinder through said head into theexhaust cylinders.

S. In a two-stroke cycle internal combustion engine. in combination. aworking cylinder: a piston working in said working cylinder: an inletport provided in said working cylinder and overrun bysaid piston; a pluvrality of exhaust cylinders communicating with the combustion chamber ofsaid working cylinder; a piston working in each of said exhaustcylinders; an exhaust port provided in each of said exhaust cylindersand overrun by the piston working therein; and means to provide a smoothand unimpeded passage of the exhaust gases from said working cylinderinto said exhaust cylinders.

9. In a two-stroke cycle internal combustion engine. in combination. aworking cylinder: an admission port` for said working cylinder: means tocontrol said admission port a plurality of exhaust cylinderscommunicating with the combustion chamber of said working cylinder; apiston working in cach of said exhaust cylinders; an exhaust portprovided in each of said exhaust cylinders and overrun by the pistonworking therein: and means to provide a smooth and nniinpeded passagefor the exhaust gases from said working cylinder into said exhaustcylinders.

In testimony whereof. I have signed my naine to this specification inthe presence of two subscribing witnesses.

ERNST HIRLBRINK.

Witnesses 'oLDI-:Mxn .H xUPT, HENRY HASPER.

